Admin Login Page redirects to 404 Page not found

I was trying to access admin panel in nopcommerce 4.1 using https://localhost:15536/Admin. Since i wasn't logged in it redirected. But its redirecting to 404 page not found instead of login page. When i check the  URL for admin login it was "http://localhost:15536/account/login?returnUrl=%2Fadmin" instead of "http://localhost:15536/login?returnUrl=%2Fadmin" which is the correct URL. So how will i change the first URL to the second ? Any help is appreciated.
Thank you.

Not sure if something to do with you using https:// ?

I went http://localhost:15536/Admin
It worked fine for me - URL was then http://localhost:15536/login?ReturnUrl=%2Fadmin
Logged in and then goes to admin

Its was working like that for me too. But all of a sudden this happened when i try to login like 2 weeks back. And from that day its redirecting to "http://localhost:15536/account/login?returnUrl=%2Fadmin" instead of "http://localhost:15536/login?returnUrl=%2Fadmin"

Have you installed a different theme ?

Here is the code that should be in \Presentation\Nop.Web\Views\Shared\Components\AdminHeaderLinks\Default.cshtml

     <a href="@Url.Content("~/Admin")" class="administration">@T("Account.Administration")</a>

Yes, i have used two different themes other than nop commerce default theme. And i checked the /presentation/nop.web/views/shared/components/adminHeaderLinks/Default.cshtml
       @if (Model.DisplayAdminLink)
        {
            <a href="@Url.Content("~/Admin")" class="administration">@T("Account.Administration")</a>
        }
The above link is already present in that file.

nnicholas wrote:
That was what I was refering to - Does it do it when the nop commerce default theme is selected ?

Tried it with the default theme but still its redirecting to "~/Account/login" instead of "~/login"